The present invention relates in general to assemblies for use with machine frames of scraper-chain conveyors and more particularly to assemblies and arrangements which employ chain stripper devices for separating a chain from a chain wheel or sprocket.
In underground mineral mining installations, it is known to employ a frame at one end of a scraper-chain conveyor which supports drive means driving the scraper-chain assembly as well as a chain used to haul a winning machine such as a plough along the mineral face. The machine drive chain is usually entrained around a chain or sprocket wheel disposed in a housing called a `plough box` at one side of the frame. In order to ensure that the chain is separated from the chain wheel, it is known to use a stripper device which has a blade or tongue of arcuate shape which projects into the peripheral profile of the chain wheel. The stripper device is detachably mounted within the plough box. Similar stripper devices can also be employed to separate the scraper-chain assembly from its drive drum.
The plough box itself is quite narrow and this presents problems in fitting and dismantling the chain stripper device. It is known to use a two-part stripper device which is fitted to a horizontal wall in the plough box by means of bolts. An example of such an arrangement is described in U.S. Pat. No. 3,871,513 (Georg et. al) granted 18, Mar. 1975. Another problem encountered in these assemblies is that of compatability. Chain wheels of various sizes are used and the chain wheels are interchanged and replaced from time to time. Hence, stripper devices of corresponding dimensions need to be provided. It is also common to provide main and auxiliary drive stations for the conveyor and the plough box can be optionally arranged at one or other of the associated machine frames at the ends of the conveyor with the chain direction reversed. To provide for this the stripper device and its mounting arrangement needs to be appropriately symmetrical.
A general object of the present invention is to provide an improved chain stripper device and associated plough box assembly.